Kenzen Koi Food Primary Diet sinking food is an all-natural, no-filler diet designed to build Koi with excellent body confirmation and increased muscle mass. It includes highly digestible ingredients like herring meal and potato starch that minimize fish waste for a cleaner pond and encourage Koi growth. A exclusive blend of Bioceuticals (micronutrients) improves luster and help your Koi maintain a strong immune system, mitigating risk of bacterial and parisitic infection.